CentOS - Mar 2005 - How to get hot-swap SCSI disks working with hotplug

Hi, I installed Centos 4.0 on a Dual P3/1GB machine with 2 IBM 9GB SCA
disks (sda and sdb) . I have the following partition layout

/boot (raid1 on /dev/md0 = /dev/sda1, /dev/sdb1)
swap  (raid1 on /dev/md1 = /dev/sda2, /dev/sdb2)
/     (lvm on raid1 on /dev/md2 = /dev/sda3, /dev/sdb3)

hal,udev,hotplug packages I have are

hal-0.4.2-1.EL4
udev-039-10.8.EL4
hotplug-2004_04_01-7.2

df -h output is

Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00 7.6G  1.1G  6.2G  15% /
/dev/md0              289M   17M  258M   7% /boot
none                  506M     0  506M   0% /dev/shm

I used the instructions here

http://lists.us.dell.com/pipermail/linux-poweredge/2003-July/014331.html

to get grub installed on both disks MBR so I could pull out either disk
and the system would boot up.

Then, I rebooted the system and whilst it was booting up, pulled out one
disk. The system came back up correctly and I got a root shell.
/dev should on /dev/sda[1,2,3]. Then I hot-inserted the disk expecting
udev/hotplug to detect the disc insertion and create the device nodes.

However, nothing should up in /var/log/messages, dmesg and /dev.
A reboot with both disks inserted brought the system up with md1 being
synced and I then used
mdadm /dev/md0 -a /dev/sda1
mdadm /dev/md2 -a /dev/sda3

to hot add the partitions on the disc inserted.

Did I miss any steps which should have led to the creation of
/dev/sdb[1,2,3] when I hot-inserted the disc in the first place ? Has
anybody got working hot-swap scsi with CentOS ?

Regards, Yusuf
--
Yusuf Goolamabbas
yusufg@outblaze.com